SNUMAP system is portable, finger-worn, battery powered device that contains MEMS (micro-electro-mechanical system) hybrid motion sensor (three-axis accelerometer and three-axis gyroscope). The SNUMAP device consists of a wrist module and finger module, which attaches to an patients's finger and transmits three dimensional motions to a wrist module for storage and further analysis. The aims of this study is to assess tremor severity using tri-axial accelerometry and gyroscope to determine the reliability and the correlation with clinical measurements.